no previous
no next



  ― 4 ―

No. 148: Eucalyptus odorata,

Behr and Schlecht.

Western Peppermint.

(Family MYRTACEÆ.)

Botanical description.

— Genus, Eucalyptus. (See Part II, p. 33.)

Botanical description.

— Species, E. odorata, Behr and Schlechtendal in Linnea xx, 547 and 657 (1847).

A small or moderate-sized tree, with a dark grey, rough, persistent bark. (F. Mueller.)

Leaves lanceolate, usually narrow, but sometimes broad, rarely above 4 inches long, rather rigid, the veins oblique and sometimes very much so, and not close, the intramarginal one at some distance from the edge.

Peduncles mostly axillary, rather thick and short, but scarcely angular.

Pedicels, sometimes scarcely any, and rarely as long as the calyx-tube.

Calyx-tube campanulate, about 2 1/2 lines long, and as much in diameter.

Operculum hemispherical or obtusely conical, shorter than the calyx-tube.

Stamens 2 to 3 lines long, all perfect, very flexuose and slightly inflected in the bud anthers very small, with globular distinct cells, opening in pores or short oblong slits.

Ovary flat-topped.

Fruit obovoid-truncate, about 2 lines diameter, slightly contracted at the orifice or almost urceolate, tapering at the base, the rim not broad; the capsule deeply sunk. (B.Fl. iii, 215.)

Variety Woollsiana, Maiden in Crit. Rev. genus Euc., Vol. ii, 32 (1910).

A medium-sized tree.

Bark. — Whitish-grey like that of E. hemiphloia, and persistent, as in that species, on the trunk and main branches.

Timber. — Brown-coloured and interlocked.

Juvenile leaves. — Linear-lanceolate, say 4 inches long and 1/4 inch broad, dull on both sides, venation distinct though not conspicuous, except as regards the midrib. Intramarginal vein a little distant from the edge, venation spreading.

Mature leaves. — Narrow lanceolate, say 4 inches long and up to 1/2 inch broad, shining or dull-shining (egg-shell lustre) on both sides; venation as in juvenile leaves.

Buds. — Not angular, with conical operculum, the calyx tapering into the pedicel.

Flowers. — Anthers identical with those of the type; the stigma slightly dilated.

Fruits. — Small, conoid to subeylindrical, inch long, tapering to a pedicel rather exceeding that length to a common peduncle of inch; rim distinct, sometimes white; valves usually four, well sunk.




  ― 5 ―

There are two other varieties of this species, viz., calcicultrix, F.v.M., and purpurascens. Maiden, but they are both confined to South Australia as far as is known at present. Full particulars of these forms may be obtained from my "Critical Revision of the genus Eucalyptus," Vol. ii, Part 1.

Botanical Name.

— Eucalyptus, already explained (see Part II, p. 34); Odorata, Latin, smelling, hence sweet-smelling or odoriferous.

The original describers say: "Its leaves are filled with abundant volatile oil, and smell strongly when it is inclined to rain."

Vernacular Names.

— In South Australia the typical form is most generally known as "Peppermint" and sometimes as "Box Gum."

A scrubby form of the typical species is known about Adelaide as "Black Mallee."

The typical form has been sent to me from the Wyalong district as "Mallee Box" or "Box Mallee," also as "Grey Box," but it must not be confused with Eucalyptus hemiphloia, var. microcarpa (the small-fruited Grey Box). I have recommended the name "Western Peppermint" for typical odorata.

The Woollsiana variety has also been sent under the names of "Mallee Box" (e.g., from the Cobar district), and "White or Grey Box" from Gilgandra. But the commonest name for this variety, and the one I recommend for adoption, if it be desired to discriminate between the two forms (which is not easy, as they run into each other), is "Narrow-leaved Box."

Leaves.

— The tree was named, as has already been indicated, because of the odour of the oil extracted from its leaves. Following is a brief account of some observations on the oil.

Baron von Mueller found that 1,000 lb. of twigs of this tree (comprising, perhaps, 500 lb. of leaves) yielded 112 1/2 oz. of essential oil. Bosisto (Trans. Roy. Soc. Vict., vol. vi, 54, 1861-4), in part, however, gives the following figures: 100 lb. of leaves from trees growing on elevated spots yielded 4 oz. 13 drs. of oil, of specific, gravity .922, while the same quantity of leaves from trees growing on low, swampy lands, yielded only 5 1/2 drs. of oil of specific gravity .899. It is pale yellowish, with a greenish tinge, and an aromatic, somewhat camphoraceous smell. It boils between 157° and 199°.note

Quoting my book, Messrs. Schimmel & Co. say that the yield of oil from fresh leaves amounts to 1.4 per cent. The light yellow oil has an aromatic camphor-like taste and smells after cineol and Roman Carroway oil. Specific gravity 0.899 to 0.925; slightly lævogyrate. It boils from 157°–199° (Bosisto), and is often so rich in cineol (identified by the hydrobromic acid compound) that it solidifies in a freezing mixture without being fractioned.




  ― 6 ―
From the rectification residue a considerable amount of cuminic aldehyde was separated by means of its bisulphite compound. It was identified by oxidation to cuminic.note

Messrs. Schimmel & Co's. own figures, obtained from a South Australian specimen, are, specific gravity of crude oil .093 at 16° C, rectified oil .909 at 18° C. No phellandrene could be detected.

In Schimmel's Semi-Annual Report of October-November, 1903, p. 36, is a discussion as to whether an oil of this class does (Schimmel) or does not (H. G. Smith) contain cuminic aldehyde.

Messrs. Baker and Smithnote give the following result of examination of this oil:

   
Specific Gravity at 15°C. Specific Rotation. [a]D Saponification Number. Solubility in Alcohol. Constituents found. 
0.9042  +2.43°  3.41  1 vol. 80 per cent.  Eucalyptol, pinene, aromadendral. 

Bark.

— Hard, scaly, or sub-fibrous, furrowed in the case of larger trees. Branches smooth or nearly so. It is often of that peculiar character known as "Peppermint." It is very commonly intermediate in character between that of an Ironbark and a Box, hence the name "Ironbark Box," which is sometimes applied to it in New South Wales, and which is descriptive. The height to which the scaly or sub-fibrous bark occurs up the trunk varies.

Timber.

— The timber is pale or fawn brown in colour, though sometimes darker, with sap- wood of a dull white where present-old trees often showing no difference in colour. It is heavy, dense, and hard to work with plane or any other tools. Being usually cross-grained it makes the very best of mauls, and is one of the most valuable of firewoods. It is used for posts which last — when obtained from trees of fair size — for about fourteen years, though the scrub form, called often "Black Mallee," is comparatively worthless for that purpose.

Trees of this Gum are in most instances too hollow to give timber for construction purposes of any size, but it is well adapted for bearing considerable strain in all directions, where obtainable in large dimensions. Sound mature timber weighs 70 lb. per cubic foot seasoned. (W. Gill.)

Exudation.

— Friable and brownish.

Size.

— A shrub or medium-sized tree, rarely a very large tree. Sometimes mallee-like, but not a true Mallee.




  ― 7 ―

Habitat.

— This tree is chiefly found in South Australia, where it is one of the commonest trees, and is usually an indication of good wheat-growing land.

The Peppermint Gum (Euc. odorata) has a wide distribution in South Australia, being found as far north as the Flinders Ranges, near Quorn and Port Augusta, 180 miles north of Adelaide, as the bird flies, and as far south as Bordertown, on the overland line to Melbourne, 160 miles south-east of Adelaide, while the distance from west to east over which it occurs, taking Spencer's Gulf as a starting base, will usually not exceed 100 miles in width.

It also occurs on Eyre's Peninsula, near Pt. Lincoln, and likewise on Kangaroo Island.

In some places, notably Mount Remarkable and Adelaide neighbourhoods, it grows into a fine tree, but in others merely develops a stunted form which degenerates into mere scrub in many of the Mallee districts. — (Extract from letter from W. Gill, Conservator of Forests, Adelaide. — 3/3/10.)

It also occurs in north-western Victoria, but as regards New South Wales its range requires to be more clearly defined. It is a "dry country" species. It has been recorded from Deniliquin, Wyalong, Cobar, Nymagee, and other places.

The variety named after the Rev. Dr. Woolls has been received from Mount Boppy near Cobar, Girilambone to Condobolin, Dubbo to Baradine and the Castlereagh River, Narrabri, Pilliga, and Denman.

Propagation.

— It readily grows from the stools after coppicing, and therefore proves profitable for firewood within easy range of a good market. (W. Gill.)

EXPLANATION OF PLATE 152.

Plate 152: Western Peppermint (Eucalyptus odorata, Behr.) Lithograph by Margaret Flockton.



Variety Woollsiana, Maiden.

  • B. Sucker leaves from type, Narrabri, New South Wales.
  • C. Twig with young buds and small fruits, from type.
  • D. Anther.

TYPICAL FORM.

  • A. Sucker leaf from Wirrabara, near Mount Remarkable, South Australia.
  • E. Flowering twig from Cobar, New South Wales.
  • F. Fruits from St. Vincent's Gulf, South Australia (W. Gill).
  • G. Anther.
  • H. Buds from type, "Sud Australie, 1848."
  • K. Juvenile leaf from type.
  • L. Juvenile leaf from the National Park, near Adelaide (W. Gill), nearly orbicular in outline. The juvenile leaves are usually narrow, and a specimen like this shows that the juvenile leaf varies like other characters in Eucalyptus.
  • M. Mature leaf.

NOTE. — The mature leaf of (A) normal form, cannot he separated from that of (C) type of variety Woollsiana.

PHOTOGRAPHIC ILLUSTRATIONS.

"Black Mallee" (Eucalyptus odorata). Nackara Creek, Hundred of Coglin, South Australia. — (W. Gill, photo.)



Eucalyptus odorala growing on Mount Brown Forest Reserve, about 9 miles south of Quorn, South Australia. — (W. Gill, photo.)



Saplings of Eucalyptus odorata, var. Woollsiana, at Gilgandra, New South Wales. — (R. H. Cambage, photo.)



Footnotes Issue No. 148.

no previous
no next